The invention relates to an apparatus and method for the continuous casting of metal, especially with a casting machine having circulating or roller molds, the metal flowing as a melt out of a nozzle, if appropriate with a nozzle mouthpiece, between the molds and solidifying between side-limiting elements.
For the continuous casting, particularly, of ferrous and non-ferrous metals, machines having a mold with continuously advancing walls have been developed. These machines include those in which casting is carried out between two rotating steel bands. Machines are also known in which the casting mold is formed by a double row of mold halves which are combined into two endless rotating chains. At the casting end, the mold halves located opposite one another come up against one another and in this position move a certain distance over which they form the actual chain mold. After that, they separate from one another and meet up agains after a short time at the pouring nozzle.
Particularly in machines with chain molds for the casting of relatively thin metal strips, for example strips with a thickness of only 20 mm and below, the region round the feed nozzle and the feed nozzle itself are the parts of the entire casting installation which present most problems. This is primarily because both the mechanical stress on the parts of the installation and the stress on them as a result of the very high metal temperature are the greatest.
The molten metal or the metal strip solidifying between the molds is conventionally engaged laterally by revolving side-limiters. These side-limiters require a high outlay in terms of the cost of installation and maintenance, especially because different side-limiters are also required for different cast-strip thicknesses. In particular, their susceptibility to faults is very high because the distance between the side-limiter and nozzle and also between the side-limiter and mold must be adjusted with the highest possible accuracy and maintained during the casting operation. Furthermore, the known side-limiters do not allow the width of a cast metal strip to be changed during the casting operation. However, this is a considerable disadvantage, since it is possible to match the cast-strip width to an ordered width only to a limited extent, usually by staggering in steps. Exact cutting to width then has to be carried out by a trimming the strip, and this again results in considerable metal waste, involving further labour costs.
The inventor has made it his aim to develop an apparatus and a process of the type mentioned above, in which the width of the cast strip can be adjusted, preferably actually during the casting operation, and at the same time the flow of molten metal is controlled more efficiently. In addition, controlled lateral cooling is also to be effected.